GB1270211A - Tap changer for regulating transformers with controllable semi-conductor rectifiers - Google Patents

Abstract

1,270,211. Transformers. E. SCHEUBECK. 7 April, 1970 [12 April, 1969], No. 16422/70. Heading H1T. A tap changer for regulating transformers Tr with controllable semi-conductor rectifiers 17, 18, 19, 20 arranged in the load circuit L in two parallel-lying circuits which conduct the power current, the ignition pulses of which rectifiers are supplied through a control circuit from the voltage tapped from the transformer, and with a tap-selector W the stationary contacts of which A 1 , B 1 , C 1 , D 1 , A 2 , B 2 , C 2 , D 2 are connected with the tapped points A, B, C, D, of the transformer. The tap selector consists, for each tapping of the transformer winding, of two mutually conductively connected stationary contacts lying in two switch planes, and is provided with two movable contact members 11, 12 lying in the same two switch planes and each consisting of two mechanically coupled contacts 13, 14, 15, 16 while each contact member 11, 12 in its switch plane switches up on to the stationary contacts of the two adjacent tappings A, B, or B, C, of the transformer winding, and in doing, applies the tapped voltage, lying in each case between the two mechanically coupled contacts 13, 14 or 15, 16 of one switch plant, to a control transformer 25 or 26 for the feeding of the control circuit. The control circuit consists of AND gates 33, 34, flip-flop 32, resistor 59, 58, 57, 56 diodes 61-67 inclusive, the pulse generators 35, 36 and an electric or mechanical command emitter. Said command emitter may be a magnetic tape, a photo-electrically working punched disc, or as in the illustrative embodiment a mechanical control roll 50 coupled with the drive of the movable contact members of the tap selector. Both parallel-lying circuits of the tap changer are simultaneously conductive when no tap change is taking place. There lies in parallel to the controllable semi-conductor rectifiers 17, 18, 19, 20 a voltage detection apparatus 25, 26 in each of the two circuits St 1 , St 2 of the power change-over switch, which apparatuses feed an AND-gate 33, 34 each of the control circuit, through bridge rectifiers 29, 30, 43, 44.